Distributor cap



Nov. 2, 1937. I J. L. ARTHUR ET AL 2,097,426

DISTRIBUTOR CAP Filed Aug. 10, 1955 Fr( I I 2! we I! INVENTOR ATTORNEYS Patented Nov. 2, 1937 DISTRIBUTOR CAP James L. Arthur and William D. Schrope, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 10, 1935, Serial No. 35,603

tially as indicated by the line and arrows 5-5 of Fig. 1.

Fig. 6 is a view partly in plan and partly in horizontal section of the improved distributor cap, illustrating a modification of the lead receiving recesses.

Heretofore side outlet caps, that is distributor caps having passages for electric leads making entry on a line substantially parallel with the base of the distributor cap, have been manufactured in composite form, of which the patent to Fitzsimmons 1,956,382 granted April 24, 1934, is an example. Distributor caps of this type are very desirable for many reasons, but those constructions heretofore manufactured have been considerably at fault, in that they make way for the passage of moisture between the body and cover members and along the leads, that causes more or less corrosion and produces much failure in the electrical engagement between the distributor cap terminals and the conductive element of the lead. When moisture travels along the distributor leads until it reaches the contact ing parts of the electrical circuit, there results frequent failure of the entire system, due to either high resistance, or corrosion at the terminals.

In overcoming these difilculties, and in accomplishing the objects herein stated, there has been provided a side outlet distributor cap of a one piece or integral construction, in which novel terminal members are secured within the head portion of the cap, by molding a body of dielectric material thereabout so as to hold the inserts in place, and then drilling from the edge or periphery of the head member to make wire receiving passages that end substantially over or adjacent to the terminal inserts. As an aid to locating the drill passages, the outside surface of the head portion of the cap is provided with molded indicating means that show the relative position of the insertson the reverse side of the head portion, and these molded indicating means may include an arrow shaft or line for indicating the direction of the proposed drilling. By construction of this type, the terminal inserts may be set or positioned within a mold and the distributor cap cast about the inserts so as to anchor them in place, which results in a unit of construction that may be subsequently processed to answer the requirements of any one of several different engines. That is to say, the mold may be provided with say six terminal inserts, and the body of insulating material cast about the same.

The unit so formed may thence be drilled to provide the wire receiving recesses, thereby fash- 7 Claims.

This invention relates to ignition distributors, and is particularly directed to distributor caps of the side outlet type.

One of the objects of the invention is to provide a distributor cap that is proof against the entrance of moisture along the wires or leads attached thereto, whereby the maximum dielectric properties of the cap are assured.

Another object is to provide a distributor cap of the indicated type that is conveniently adaptable to different types of automotive engines, or to the distributors on which they are used.

Another object of the invention is to provide a side outlet distributor cap of integral formation having lateral bores or lead receiving passages.

Another object is to provide a body for a distributor cap, that may be subsequently fashioned to answer the specific requirements for any one of several different engines with which it is to be used.

Another object is to provide an improved terminal insert for distributor caps, that will insure retention of and contact with a distributor lead.

Another object is to provide a terminal member for a distributor cap that will releasably secure a terminal lead in a socket, and complete electrical connection with the conductor thereof, by drawing the body of the lead into sealing engagement, whereby the travel of moisture along the conductor to the region of the insert is prevented.

Still another object of the invention is to provide a method for making distributor caps so that the product of the method will result in a unit that will answer the specific requirements of any one of several different engines.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a top plan view of a side outlet cap embracing the invention herein disclosed.

Fig. 2 is a view partly in elevation and partly in section of the improved cap substantially as indicated by the line and arrows 2-2 of Fig. 1.

Fig. 3 is a sectional view through the cap substantially as indicated by the line and arrows 3-3 of Fig. 2.

Fig. 4 is a bottom, plan view of the cap, substantially as indicated by the line and arrows 44 of Fig. 3.

Fig. 5 is a fragmentary showing in cross section, and on an enlarged scale, showing detail-s of construction of the terminal means substane ioning the unit to fit the specific requirements of the engine on which it is to be used. In one instance, these special requirements may necessitate that all of the wire receiving recesses make entry from one side o1 the distributor cap, substantially as illustrated in Fig. 1. In another instance it may be possible or desirable to drill part of the wire receiving recesses from one side or the cap and part from the other side, substantially as indicated in Fig. 6. In still another instance, it may be desirable to have all of the wire receiving recesses extend in a radial direction, and still other instances may necessitate various combinations of these drillings. However, the one molded unit, after being cured' may, by a subsequent working, be caused to answer the re quirements of any one of the specified types. 7

For more detailed explanation of the invention, reference is had particularly to the drawing wherein l0 represents a distributor cap having a head portion i2 and a skirt portion i l of integral formation. The skirt portion is formed of a diameter to fit the distributor cup with which it is to. be used, and usually terminates with aflange 56 having a rabbeted edge or shoulder I8 for mating up with the edge of the distributor cup, the flange It usually passing within the cup. At diametric points near the edge of the skirt there are provided recessed lugs 26 for the reception of holddown springs by which the cap is retained on the distributor cup. In one of these lugs and set into the portion l8 there is provided one or more locating pins 22 that are adapted to mate up with a notch or other provision at the edge or the distributor cup.

The head portion l2 of the cap is here relatively thick in dimension. The outer surface is preferably rounded or inclined to provide a good water shed, and the inner face is corrugated or grooved concentric thereof so as to embrace a central portion 2 5, with two concentric and outwardly disposed ribs 26 and 28. Outside of the rib 28 and situated between it and the skirt Hi there is a circular row of bosses 30, in the illustrated embodiment there being six in number. The concentric ribs with the surrounding bosses tend to increase the surface distance between any two of the terminals and thereby aid in preventing a short circuiting, or transmission of current from one terminal to another. Anchored within each. of the bosses 36 there is a terminal member 32 that has special provisions for receiving portions of the moldable composition by which it is anchored in place. Likewise within the central portion 24 there is moldably secured a terminal member des ignated at 3%. The outside or rounded surface of the head is provided with moldings directly oppo-' site and substantially centered with the inserts 32 and 36, the moldings here being raised on flat portions indicated at 33. have lineal extensions as the raised ridges or arrow shafts shown at 35, that will indicate the direction and plan of passage drilling.

Specifically, the terminal members 32 constitute a conductive block having a bore 36 at least a portion of which is threaded as at 38 to receive a screw terminal. The block also provides a web like portion 39 that is preferably of arc like formation substantially as indicated at Fig. 4, and when set in place answers as the terminal portion cooperating with the rotor segment. In the illustrated embodiment, this web ll extends from the block substantially parallel with the axis of the threaded bore. The periphery of the block is provided with a recess, annular groove,

These moldings may or other suitable depressed or roughened configuration 32, so as to provide anchorage for the molding composition by which the block is retained in place. The terminal also consists of a conductive block that has the roughened or recessed portion 3 3 by which it is anchored in place and is also provided with a threaded bore it for the reception of an appropriate terminal pin. In addition, the terminal 35 is recessed as at 38 so as to receive a contact button 5% which may be secured in place by staking or unching as at 52.

For cooperating with the terminal members 32 and 34, there are provided terminal pins 54 and 58 respectively, each of which constitutes a bipitched, or difierentially threaded member. These threaded members are essentially the same except for the threaded portions and therefore specific description of one will sufiice for both. With reference to Fig. 5, it will be observed that the pin is provided with a relatively fine or close pitched threaded portion 66), which for purposes of illustration may be said to be a machine thread screw, and is also provided with a second-or more widely pitched threaded portion 62, which for the purpose of illustration may be said to be a wood screw thread. The basic idea is that the pitch of the thread at the portion 6% will be much less than the pitch of the thread at the portion 82, and so that the pitch of the threadfifl will match up with the pitch of the threaded portion 38 of the terminal body. 7

In constructing the distributor cap, the inserts are arranged within appropriate recesses of the molds where they are secured in position by the aid of locating pins passing through the threaded apertures thereof. In some instances, it may be preferred to use the terminal screws 5 and 56 for such locating pins. In the form illustrated it is desirable that all of the inserts 32 be symmetrically arranged, and disposed coincident with a common plane, so as to be substantially equally spaced from a medial plane passing through the head of the cap dividing the same into substantially equal halves or discs. It is also desired to locate the insert 36 centrally of the head portion and have it of sufiicient length to be cut by. this said medial plane. The subsequent drilling for the lead will then form a bore 5'? through the insert 3 3 for the reception of the end of the lead. By this arrangement, then all of the inserts 32 will be wholly located upon one side of the plane, and the insert 34 will have.

a material portion thereof on both sides, and all of the inserts will have portions exposed at the inner surface of the cup. After arranging the inserts in place the mold members are charged with the necessary pills, preforms, or other batches of molding material and brought together with the attendant application of heat and pressure under which conditions the nonconducting material is caused to flow about the inserts and solidify in contact therewith, so that and holes are drilled in the head portion so as to extend from some point on the periphery thereof, as at Ill, 12, 14 etc., and directed inwardly of the head so as to pass in close. proximity to, and end substantially over or in spaced proximity to the end of one of the inserts 32. The direction and extent of the drilled holes will depend upon the needs of the equipment with which the cap is to be used. The moldings 33 will designate the location of the inserts, and the molding 35 when used will be a guide to the drilling. In Fig. l, the plan of drilling holes for leads to the inserts 32 is indicated by the dashed lines, and substantially embraces the drill holes 16, 18, 82, 84, 86, and 88 all making entry from one side of the cap. These drilled passages may be arranged in any convenient manner that will answer the specific requirements of installation for any one of several difierent types of engines, as will be seen upon further reference to the drawing. In Fig. 6, a modification of the drilling plan is illustrated. where the passages are shown as 89,92, 94, 96, S8, and H part of which enter from opposite sides of the cap. Particular installations might require other types or plans of drilling, or combinations thereof, but it is believed that the types of passages illustrated, will demonstrate the feasibility of any combination. That is to say, the drilling might consist of pure radial drill-ways as indicated at 80, or it might consist of branch or deflected drill-ways as indicated at 82 and 84, or again the drilling might consist of the chord type such as illustrated at l5, 18 etc. The branched or deflected drill-way, as illustrated at 82 and 84, is accomplished by drilling into the head from opposite sides, the angle of drilling being such that the drill holes intersect to provide a communicating passage. Since it is here proposed that the wire extend out from the passage 84, it is desirable to plug up the end of the drill-way 82 by inserting a plug I02 which can be cemented in place. Drilling for the central terminal 34 is made as indicated at Hit and may be started at any convenient or desirable point on the periphery of the cap. The rill-trig for this passage will encounter the insert 3-4 of the inner end, which when drilled will be adapted to receive the lead from the coil.

With the distributor caps so constructed, provision is made for both mechanically securing and electrically connecting the insulated conductors, such as i l 0, with the various distributor terminals. The conductors l I!) are, by reason of the drilling of the wire receiving passages, just a nice fit and are easily insertable within the drilled passages, and when so adjusted as is i1- lustrated in Figs. 1, 3, 5, and 6, are held in place by inserting the pin 54 or 56 and threading it into the insert 32 or 34 respectively. This causes the sharpened or pointed portion 62 to pierce the insulation of the conductor, and as the screw is run into place, the pitch of the thread 62 being much coarser than the thread 6!! the point causes the insulation and the conducting wire to be drawn down against the bottom of the recess or drill-way substantially as indicated at Fig. 5 the point 52 eventually piercing the stranded Wire iii of the conductor. Thus electrical contact is made between the pins 54, or 56 and a wire of the conductor, and the insulation between the conductor and the bottom of the drill-way is pinched or forced together so as to prevent moisture entering between the wire and bottoms of the drill way, or the moistening of the metallic parts of the terminal.

While the drawing illustrates a cap for a six cylinder engine, the invention is not limited thereto, but is fully applicable to caps for four, eight, twelve and any other number of engine cylinders. The illustration of a cap for a six cylinder engine is not therefore to be construed as a limitation, but fully illustrative for the whole field of distributor caps, regardless of the number of terminals the same may have.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to-be understood that other forms might be adopted, all coming within the scope of the claims-which follow.

What is claimed is as follows:

1. A terminal support for an insulated cable comprising in combination, a body of molded insulating material having a relatively thick wall, conductive members secured within the end wall as inserts with the material of the body molded about recess portions of the inserts, said end wall having bores extending inwardly from the peripheral edge surface, each to end after passing over one of the inserts, and bi-pitch threaded members each threaded through an insert and projecting laterally across the inner end of the respective bore.

2. A terminal support, provided with an annular series of spaced terminals secured as inserts in and projecting from a body of insulation, and provided with cross bores extending from an edge thereof arranged in a common plane and each passing over the end of an insert, and means threaded through each insert and projecting into the end of one of the cross bores, said means being provided with screw threads of different pitch upon its end adapted to be threaded into a con ductor disposed in the cross bores.

13. In a terminal support, the combination comprising, a terminal insert including a body of conducting material having a threaded aperture and peripherally recessed portions, a body of nonconducting material molded about the insert so as to engage the recessed portions thereof, said body having a lead receiving bore arranged to pass by the end of the insert, with a bore extending from the threaded aperture of the insert to open into the lead receiving bore and a bi-pitched screw device disposed in the bore of the insert and projecting into the lead receiving bore.

4. A terminal support comprising in combination, a body of molded insulating material having a relatively thickened head portion, a plurality of terminal members anchored within the head portion and providing extensions exterior thereof, said inserts being substantially flush with the inner face of the head member and extending short of the medial plane passing through the head member, said head member having a plurality of bores extending from the edge thereof inwardly to pass over each insert, all of the bores being arranged substantially coincident with the medial plane, and adapted to receive an insulated conductor, and bi-pitched threaded means passing through the inserts and adapted to project into the ends of the insulated conductors, whereby engagement is made between the insert and the wire of the conductor.

5. A terminal support comprising in combination, a body of molded insulating material, a plurality of terminal members symmetrically disposed within the body and having extensions embedded within the same, bores extending from the periphery of the body to end in close proximity to but spaced from the embedded end of the V 6. A terminal member adapted to anchor a' terminal members, and 'differentially'threaded pins passing-through the inserts and projecting into the bores.

and project beyond the body, whereby the insert may be secured within a block of insulating material by molding the same about'the body and so that the threaded portion of the member will project into a cross bore of the insulating body. '7'. In a cable support, a terminal'member comprising in combination, a metallic insert, a pin adjustably engageable with the insert and having a sharpened portion extending from the insert,

said insert and pin being adapted to be secured Within the body of the support so that the sharpened pin will project into a conductor receiving recess of the support, said sharpened por-' tion of the pin being provided with screw threads whereby the pin'may be pierced through the conductor and upon rotation thereof will draw the conductor firmly against the insert and make contact with the wire thereof.

JAMES L. ARTHUR. WILLIAM D. SCI-IROPE. 

